On Thu, 18 Dec 2008 13:01:22 -0600, Lloyd E. Sponenburgh wrote:
"SteveB" toquerville@zionvistas fired this volley in

My grandkids have an electric atv. The battery is kaflooey, and I need
to get another. It is a 12v. 8ah, and says cautions on battery acid.
So, apparently, it is an acid battery. It is pretty much sealed. It is
approx. 2.5"w x 4"h x 6"l. I was wondering if I
could
just get a battery like is used in atvs or motorcycles or such and
use
that, giving it more riding time. These can be put in two at a time if
properly connected. Not sure + to - or + to +, but the
directions
will have that. Do you think that would be too much battery?

You can get 12v motorcycle batteries in the 20Ah range. They might not
fit exactly in the hole you have, but would be interchangable in terms of
voltage, and would last twice as long as what you have.

If you're using multiple batteries, and they're all 12V types, put them in
parallel. That is, put - to - and + to +.

I wouldn't use a motorcycle battery. That's got motor-starter technology
(i.e., high cold cranking amps, but don't like to be discharged as much
as a "deep-cycle" battery, like marine, RV, golf cart, etc.) These are
designed to be charged then maintain a constant discharge until they're
empty, at which time you swap them out for the ones that have been on the
charger since the last swap, or either just set the toy aside and plug it
in to charge overnight or whatever.

And yes, to maintain the same voltage but double the amp-hrs, put two
in parallel: + to + to +, and - to - to -.

If it wants 12V, and you have 6V batteries, you'd put them in series -
i.e. negative of one 6V battery to negative of the device, positive of
that battery to the negative of the other 6V battery, and positive
of it to positive of the device.

Have Fun!
Rich